I was going to do a build for my first AR, but instead I bought an M&P Sport... Had a good reputation for reliability, so I went that route. Just hit 1k rounds, no failures. Good staking on gas key and castle nut, great fit/finish, decent trigger, M4 feed ramps, individually-MPI and batch-HPT bolt, chrome-lined BCG, Melonite-lined barrel, F-Marked FSB and originally came with a Magpul MBUS rear... I have no complaints, given the $560 I paid. I couldn't care less about having a dust cover or forward assist.
Added the grip for $15, comp for $75, BCM extended charging handle for $45, and I saw the rail on sale at Midway, and also had a good amount of Midway Money, so that cost me all of $80, and also free-floated the barrel while offering a much more ergonomic setup...
Already had the foregrip, stock, and sling, and got the LaRue rear sight as a gift, so I've got about $775 in the whole thing (Aimpoint and WML don't count as part of the cost). Again, no complaints whatsoever.